Apparatus for applying low pressure advance and high pressure squeeze in the hydraulic operation of die casting dies



Feb, 1957 a. H. MORIN 2 780,3

APPARATUS FOR APPLYING LOW PRESSURE ADVANCE AND HIGH PRESSURE SQUEEZE INTHE HYDRAULIC OPERATION OF DIE CASTING mas Filed July 16, 1951 I .lll

INVENTOR LOUIS H. MORIN 9 a a 2 a w a a e m. a 6 y w g MO 0L .E 4 "m 1 7li/ m a m w m a ATTORN 1 2,780,836 APPARATUS FOR APPLYING LOW PRESSUREAD- V NC H GH ES URE SQU E THE RAUL AT Q .13 D E CA T ING DIES Louis H.Morin, Bronx, N. Y. Application July 16, 1951, Serial No. 237,008 11Claims. (CI. 18-30) This invention relates to an apparatus controllingthe operation of a hydraulic medium in such manner as to advance thedies of a die casting machine toward each other under low pressure and,further, in applying a high pressure squeeze in the final stage of dieoperation in securely retaining the dies inengagement with each otherand, further, in accomplishing these results by the use of a minimumamount of air.

More particularly, the invention deals with an appara: tus of thecharacter described, comprising an air cylinder and a hydraulic cylinderdisposed in parallel relationship to each other with a supplementallarge diameter air cylinder at one end portion of the hydraulic cylinderwith means for actuating a piston of the hydraulic cyl: inder throughthe medium of a cam driven from the piston in the air cylinder and inactuation of a second hydraulic piston through a large diameter pistondis posed in the supplemental air cylinder.

The novel features of the invention will be best under: stood from thefollowing description, when taken to gether with the accompanying drawinin which certain embodiments or" the invention are disclosed and,inwhich the separate parts are designated by suitable referencecharacters in each of the views and, in which:

Fig. l is a longitudinal sectional view through a control apparatus madeaccording to my inventiom with parts of the construction shown inelevation and with parts broken away; I

"Fig. 2 is a side and sectional view of a part of the structure, as seenin Fig. 1, and indicating the air piston in raised position; and

Fig. 3 is a fragmentary side view in section or a por- 7 tion of ahydraulic die casting machine.

In the drawing, 10 represents the cylinder casing of an apparatus madeaccording to my invention and, in this casing is a hydraulic cylinder 11and an air cylinder 12, these cylinders being arranged in parallelrelationshipto each other. Mounted andsealed in the lower portion of thecylinder 11 is a cylinder part 13 of a supplemental cylinder casing 14,having a large diameter and shallow supplemental air cylinder 15, Thecylinder 15'is closed by a sealed cap 16, the cap having a compressedair admission port 17 for the supply of compressed air to the cylinder15. The casing 14 has an air exhaust port 18.

Arranged in the hydraulic cylinder 11 is a primaryhydraulic piston 19,having an'O-ring seal, as at 20, the upper end of the piston 19 beingforked, as'indicated at 21, and in the forked portion is mounted aroller 22. The lower end portion of the piston '19 is hollow, as indicated at 23, for receiving a coil spring 24 tensioned to maintain theroller 22 in constant engagement with an operating cam 25.

The cam 25 operates in an upper recessed portion-26 of the casing 19 andis arranged upon a shaft 27, to which shaft is secured a segmentalgear;28.

Arranged in the air cylinder 12 is a piston 29, the piston having areduced portion, as indicated at'30, adjacent its lower end and beingsealed at the lower'end by an O-ring, as seen at 31. The lower end ofthe piston 29 hasa-reduced downwardly projecting portion;32, whichprovides, at the lower portion of the piston 29, an annular. airadmission passage '33 directly above a sealed disc 34 fixed to the lowerend of the cylinder 12.

rates Patent 6 2,780,836 Patented Feb. 1957 Registering with the annularair admission passage 33. is an air intake port 35, note Fig. 2; and at36 is shown a pipe leading to a suitable source of compressed airsupply, not shown, which would include an'air control valve forsupplying'and exhausting the air.

The piston 29 has an elongated reduced portion 37 having, on one surfacethereof, a rack 38 adapted to mesh with thegear segment 28 and, at theupper end of the reduced portion 37, is a .piston head 39, whichoperates in an extension 40, of the cylinder 12 formed in a supplementalcasing part 41, suitably fixed to the casing 10. The casing. part 41 hasan opening 42 registering with the recess 26 to receive the gear segment28 and cam 25. In this connection, it will be apparent thatthe cylinder12 isdisposed at one side of the cyl inder 11 for registering alinementwith the gear segment 2.8, which is disposed at one side of the cam 25.

At the top of the'casing part 41 is a cap or cover plate 43 having anaperture 4-4 therein, through which a rod 395 is adapted to pass. Therod 45 is mounted in and secured t6 the cylinder 29, as indicated at 46,the rod being disposed in a long bore 47in the reduced portioll 37a1 1d.the piston head 3.9 and mounted on the rod ii and in the bore 47 is along coil spring 48, tensioned to normally support the piston 29 in thelowermost position, adjustment of which is controlled by adjustable nuts519 secured to the upper end of the rod- 45. This adjustment is providedto definitely control movement of the piston 29 to time the applicationof the squeeze pressnre, as will be apparent. The spring 48 also servesto return the earn 255' to the normal starting position,

which is indicated in Fig. ,1 of the drawing.

Considering Fig.1? of the drawing, it will be apparent that the casing10'lias a vertical port 50 paralleling the cylinder 12 communicating atits lower end with the port 35, the plug 50' sealing the lower end ofthe port 501 The upper endofftlie port 50 communicates with a port 51'opening into the upper'end of the cylinder 12. The port 51 has a plugseal, as at 52. Above and closely adjacent the port51 is another port 53placed in com munication with the intake port 17 of the cylinder 15through a suitable piping, as at 54. Arranged in the supplemental aircylinder 15 is a large diameter disc type piston 55 having an Q-ringseal, as at 56 in the cylinder 15. i

{The piston 55 has a small diameter supplemental hydraulic piston 57,which operates in the cylinder part 13 and hasv an Qgring seal 53therein. The piston 57 nor tnallyrgests flush with the inner or upperend of the cylinder part 13" and, communicating with the cylinder 11adjacent the upper or inner end of the cylinder is a port 59, whichconimunicates through a pipe 60 to suitable. hydraulic mechanisms formoving a die member or members of a die casting machine in the requireddirections.

Hydraulically operated dies of die casting machines are known in the artand reference may be made to my United States Letters Patent No.2,567,649, issued September 11, 1951, for Hydraulic Die Casting Machine,for a more detailed description of such a machine. Briefiy, in such amachine there is a cylinder 64 which is connectednto the hydrauliccylinder 11 through the pipe 60,, The .cylinderG t contains a piston orplunger d5 upon one end of which the hydraulic fluid acts and the other,end. of the plunger engages with a movable dieholder-6 6. The die -holder carries a die member 67 at its end and when fluid-under pressureis admitted to the cylinder 64,.the. plunger and die-holder are moved ina directionitormove the diemember 67 into engagement with ,anopposingdiemember and this mechanism is also employedto maintainthe die members inengagement with each other during the casting operation.

The present invention deals basically with the control and operation ofthe hydraulic medium, so as to provide a low pressure movement of thedies into closed position and, then, momentarily applying the highpressure squeeze at the instant or moment of pressure injecting castingmaterial into the dies and, then, to immediately relieve this pressure.However, it will be understood that, where a pair of movable dies areemployed in the die casting machine, both of the die members maybeoperated by one hydraulic cylinder 11 if desired, Also, after thecasting has been completed, the die members may be separated upon therelease of the pressure in the hydraulic cylinder 11 in a suitablemanner, such as by return springs as shown in said Letters Patent.

It will appear that the spring 24 bears upon the upper end of the piston57 and, thus, serves to normally maintain the piston 55 in the depressedposition, as well as to maintain the roller 22 in engagement with thecam 25. Any suitable means will be provided for controlling the supplyof hydraulic medium to the cylinder 11. This is not shown, as it is wellknown in the art of hydraulic systems.

At 61 in Fig. l of the drawing I have indicated means for lubrication ofthe roller 22, through more or less conventional grooving and portarrangement, as diagrammatically illustrated.

The operation of my improved control mechanism will be understood fromthe foregoing description, when taken in connection with theaccompanying drawing and the following statement.

The position of the parts, as seen in Fig. 1, is at normal or what mightbe termed initial position of the mechanism, the pressure of the air inthe cylinders 12 and 15 having been released through a suitable two-waycontrol valve in the pipe 36, which is not shown.

In starting the cycle of operation, the control valve in question isopened to admit air under pressure to the port 35, which results inraising the piston 29 in the cylinder 12. This operation transmitsrotary movement to the cam 25 which gradually moves the piston 19downwardly in the hydraulic cylinder 11, operating the hydraulic mediumto actuate or close the dies.

This operation continues until the roller 22 reaches a positionapproximately at the position designated by the arrow 62, whichterminates the active movement of the cam 25 upon the roller 22. Inother words, the surface of the cam 25, between the arrow 62 and the end63, is concentric to the axis 27.

Upon reaching this position, the dies of the casting machine will havebeen moved into closed position with respect to each other by the actionof the piston 19 upon the hydraulic medium in the cylinder 11. At thatmoment, the piston 29 or the lower edge 29' thereof, forming the top ofthe recessed portion 30, will have reached a position just below theport 53; whereupon, continued motion applied to the piston 29 will raisethe same sufficiently to place the ports 51 and 53 in communicationthrough the reduced portion 30, thus admitting air to the lower end ofthe cylinder 15 to actuate the piston 55, thus moving the piston 57upwardly into the cylinder 11, which will apply the high pressuresqueeze to the dies by action upon the hydraulic medium in the cylinder11.

Immediately after the casting shot has taken place and when the piston29 has reached its upward limit of travel at a position substantiallysimilar to that shown in Fig. 2, the valve controlling the air supply,which is not shown, will be moved to an exhaust position, thus releasingthe air pressure from the cylinder 12 through the pipe 36. The airpressure in the cylinder 15 is also released in this manner through theports 53 and 51 #hich are in communication with each other at this timeand with the pipe 36. As the piston 29 moves downwardly by the spring48, the plunger 19 will be returned to normal position by action of thespring 24'which holds the roller 22 in engagement with the cam 25 as itreturns to the position shown in Fig. 1. It will also be understood thatthe spring 24 returns the piston 55 to the position shown in Fig. 1 andthis takes place immediately upon the release of air pressure in thecylinder 15. In the next cycle of operation, the foregoing steps ofactuation of the parts will take place and this is repeated in eachcycle of operation of the machine.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. In a die-casting machine having a die member that is movable underhydraulic pressure into engagement with the face of an opposing diemember and wherein casting material is injected into a casting cavityformed by said die members while said members are held in engagementunder increased hydraulic pressure, the combination of a hydrauliccylinder containing a hydraulic fluid, said cylinder having a porttherein through which pressure exerted on the hydraulic fluid istransmitted to a movable die member, a pair of pistons movably mountedin the said hydraulic cylinder for exerting pressure on the hydraulicfluid therein, one of said pistons exerting pressure on the hydraulicfluid in movement of the movable die member toward an opposing diemember, the other of said pistons exerting pressure on the hydraulicfluid when the die members are in engagement during injection of castingmaterial, the last-mentioned pressure supplementing the pressure exertedby the first piston, pneumatically operated means for moving said firstpiston in the hydraulic cylinder in a direction to act on the fluidtherein, said means including a piston connected to the first-mentionedhydraulic piston, a second pneumatically operated means for moving thesecond piston in the hydraulic cylinder in a direction to act on thefluid therein, said second pneumatically operating means including apiston connected to the supplementary piston, and valve means foradmitting air under pressure to the second pneumatically operated means,said valve means being controlled by movement of the first pneumaticpiston.

2.. In a die-casting machine, the combination as defined in claim 1wherein the pistons in the hydraulic cylinder are positioned in opposingrelation to each other and which includes a return spring interposedbetween said pistons.

3. In a die-casting machine, the combination as defined in claim 1wherein the pistons in the hydraulic cylinder are positioned in opposingrelation to each other and which includes a return spring interposedbetween said pistons, and a second return spring acting on the firstpneumatic piston, said second return spring returning the firstpneumatic piston and the hydraulic piston connected thereto to theirinitial positions upon release of air pressure from the first pneumaticpiston.

4. An apparatus of the class described, comprising a pair of movabledies, a hydraulic cylinder connected to said dies, said cylinder havingpiston means therein for actuating a hydraulic medium in movement ofsaid dies into closed position, a supplemental piston movable into saidcylinder upon completion of closing movement of the dies to apply highpressure squeeze on said dies when in closed position, means controllingoperation of the first named and supplemental pistons in said hydrauliccylinder, a coil spring disposed between said pistons for normallyreturning the same to inoperative position, the means for actuating thefirst named piston comprising a cam, an air cylinder at one side of thehydraulic cylinder, and a piston in said cylinder in operativeengagement with the cam to actuate said cam.

5.-An apparatus of the class described, comprising a pair of movabledies, a hydraulic cylinder connected to said dies, said cylinder havingpiston means therein for actuating a hydraulic medium in movement ofsaid dies into closed position, a supplemental piston movable into saidcylinder upon completion of closing movement of the dies to apply highpressure squeeze on said dies when in closed position, means controllingoperation of the first named and supplemental pistons in said hydrauliccylinder, a coil spring disposed between said pistons for normallyreturning the same to inoperative position, the means for actuating thefirst named piston comprising a cam, an air cylinder at one side of thehydraulic cylinder, a piston in said cylinder in operative engagementwith the cam to actuate said cam, and means controlled by the airactuated piston for transmitting air to means operating the suplpementalpiston of said hydraulic cylinder.

6. An apparatus of the class described, comprising a pair of movabledies, a hydraulic cylinder connected to said dies, said cylinder havingpiston means therein for actuating a hydraulic medium in movement ofsaid dies into closed position, a supplemental piston movable into saidcylinder upon completion of closing movement of the dies to apply highpressure squeeze on said dies when in closed position, means controllingoperation of the first named and supplemental pistons in said hydrauliccylinder, a coil spring disposed between said pistons for normallyreturning the same to inoperative position, the means for actuating thefirst named piston comprising a cam, an air cylinder at one side of thehydraulic cylinder, a piston in said cylinder in operative engagementwith the cam to actuate said cam, means controlled by the air actuatedpiston for transmitting air to means operating the supplemental pistonof said hydraulic cylinder, tensional means for moving the air piston inone direction and for maintaining the same in the normal inoperativeposition, and adjustable means controlling the inoperative position ofsaid air piston.

7. An apparatus for hydraulically operating a mechanism and to applypredetermined high pressure on the mechanism at a predetermined moment,comprising a hydraulic cylinder with means for placing the hydraulicmedium of the cylinder in operative communication with said mechanism tobe actuated, a primary piston in the hydraulic cylinder for actuationupon the hydraulic medium to control initial operation of saidmechanism, a supplemental piston movable into the hydraulic cylinder inapplication of the high pressure operation upon said mechanism at saidpredetermined moment, means controlling operation of said primary andsupplemental pistons, said last named means comprising an air cylinderhaving a piston, means for placing the piston in direct operativeengagement with said primary piston to impart movement thereof, meansfor admitting air to the air cylinder for actuation to the pistontherein, said supplemental piston having a large piston element arrangedand operating in a supplemental large diameter air cylinder, and meanscontrolled by the piston in the air cylinder for directing air underpressure to the supplemental air cylinder in actuation of saidsupplemental piston in the hydraulic cylinder.

8. An apparatus for hydraulically operating a mechanism and to applypredetermined high pressure on the mechanism at a predetermined moment,comprising a hydraulic cylinder with means for placing the hydraulicmedium of the cylinder in operative communication with said mechanism tobe actuated, a primary piston in the hydraulic cylinder for actuationupon the hydraulic medium to control initial operation of saidmechanism, a supplemental piston movable into the hydraulic cylinder inapplication of the high pressure operation upon said mechanism at saidpredetermined moment, means controlling operation of said primary andsupplemental pistons, said last named means comprising an air cylinderhaving a piston, means for placing the piston in direct operativeengagement with said primary piston to impart movement thereof, meansfor admitting air to the air cylinder for actuation to the pistontherein, said supplemental piston having a large piston element arrangedand operating in a supplemental large diameter air cylinder, meanscontrolled by the piston in the air cylinder for directing air underpressure to the supplemental air cylinder in actuation of saidsupplemental piston in the hydraulic cylinder, and a coil springoperatively engaging the primary and supplemental pistons for movementthereof into inoperative positions in the hydraulic cylinder.

9. An apparatus for hydraulically operating a mechanism and to applypredetermined high pressure on the mechanism at a predetermined moment,comprising a hydraulic cylinder with means for placing the hydraulicmedium of the cylinder in operative communication with said mechanism tobe actuated, a primary piston in the hydraulic cylinder for actuationupon the hydraulic medium to control initial operation of saidmechanism, a supplemental piston movable into the hydraulic cylinder inapplication of the high pressure operation upon said mechanism at saidpredetermined moment, means controlling operation of said primary andsupplemental pistons, said last named means comprising an air cylinderhaving a piston, means for placing the piston in direct operativeengagement with said primary piston to impart movement thereof, meansfor admitting air to the air cylinder for actuation to the pistontherein, said supplemental piston having a large piston element arrangedand operating in a supplemental large diameter air cylinder, meanscontrolled by the piston in the air cylinder for directing air underpressure to the supplemental air cylinder in actuation of saidsupplemental piston in the hydraulic cylinder, a coil spring operativelyengaging the primary and supplemental pistons for movement thereof intoinoperative positions in the hydraulic cylinder, and a coil spring foroperating the air piston in one direction in said air cylinder.

10. An apparatus for hydraulically operating a mecha nism and to applypredetermined high pressure on the mechanism at a predetermined moment,comprising a hydraulic cylinder with means for placing the hydraulicmedium of the cylinder in operative communication with said mechanism tobe actuated, primary and supplemental pistons at opposed ends of saidcylinder, tensional means between said pistons normally maintaining thesame in spaced relationship to each other, cam means for moving theprimary piston in said cylinder in normal operation of said mechanism,and means comprising a large diameter piston in an air cylinder,including a supply of air to actuate the piston in said air cylinder inoperating the supplemental piston in the hydraulic cylinder in applyinghigh pressure operation to said mechanism.

11. An apparatus for hydraulically operating a mecha nism and to applypredetermined high pressure on the mechanism at a predetermined moment,comprising a hydraulic cylinder with means for placing the hydraulicmedium of the cylinder in operative communication with said mechanism tobe actuated, primary and supplemental pistons at opposed ends of saidcylinder, tensional means between said pistons normally maintaining thesame in spaced relationship to each other, cam means for moving theprimary piston in said cylinder in normal operation of said mechanism,means comprising a large diameter piston in an air cylinder, including asupply of air to actuate the piston in said air cylinder in operatingthe supplemental piston in the hydraulic cylinder in applying highpressure operation to said mechanism, an air actuated piston controllingoperation of said cam means, and means on said last named pistoncontrolling supply of air to said first named air cylinder.

References Cited in the file of this patent UNITED STATES PATENTS2,173,583 Forichon Sept. 19, 1939 2,355,613 Wacker Aug. 15, 19442,356,634 Von Opel Aug. 22, 1944 2,396,539 Smith et al Mar. 12, 19462,569,174 Kardorfi Sept. 25, 1951

